Abstract:

The repellent action and contact action of the extracts of 21 species of plants to adult maize weevil, Sitophilus zeamais Motschulsky were studied. The results showed that petroleum ether extract of Alpinia officinarum, acetone extract of Curcuma longa and petroleum ether extract of Litsea cubeba had obvious repellent action to adult S. zeamais. Sixty hours after treatment, the average repellency class of the three extracts all reached class Ⅴ, while their average repellency was 80.02%, 80.60% and 81.70% respectively. The extracts of Acorus gramineus and Croton tiglium all had obvious contact action to adult S. zeamais, and the corrected mortalities of the weevil were all above 90% four days after treatment in the concentration of 7.86 mg/cm².

Key words: Plant extracts, Sitophilus zeamais, repellent action, contact action